“Tag” is the term commonly referred to in the wireless communication industry as the physical embodiment of the information containing device. A tag can refer to a visual tag, a Radio Frequency Identification (RFID) tag, an audible tag or the like. In practice, the tag is interrogated by a corresponding device in order for the information to be wirelessly communicated and read by the receiving device. For example, in RFID communication, the term “tag” refers to a transponder, which is an integrated circuit containing the RF circuitry and information to be transmitted. The RFID tag is typically contained within relatively compact packages, such as embedded within a credit-card type package, a key fob or the like. The compact nature of the tags makes them highly portable and adaptable to many different applications. However, the compact nature of the tag tends to limit the size of the memory unit and, thus, the amount of information that can be stored and transmitted by the tag is limited. Typically, current tags are limited to a memory size of less than about 128 bytes of storage space. In addition to physical constraints, tags are typically high-volume, low cost devices that are generally disposable. Thus, even though the physical size of the tag may allow for additional memory space, the cost related to adding additional memory is typically economically prohibitive.
In other wireless communication mediums visual tags are utilized that implement a visual symbology, such as barcoding, as the data storage unit. The visual tag may take the physical form of a label, ticket or the like having a printed visual code imprinted on the tag. Barcodes can either be one-dimensional, i.e., linear, such Universal Product Code (UPC), Code 128 or the like, or barcodes can be two-dimensional in nature, such as DataMatrix, MaxiCode, Quick Response (QR) code or the like. While 2D barcodes afford for a much greater amount of information storage capacity than conventional linear barcodes, all visual codes are relatively limited in the amount of data that they contain and subsequently transmit because the physical size of the tag is generally restrictive. Additionally, error checksum and error correction information is generally stored alongside the payload information further limiting the amount of data stored in the barcode.
Many handheld devices are typically equipped with various forms of wireless communication. For example, cellular telephones are becoming multi-faceted communication devices, no longer limited to wireless cellular communication, they may additionally provide for RFID communication, Bluetooth® communication, IR (Infrared) communication and the like. An additional short-range data communication mechanism can be implemented by equipping one handheld device with image capture means, such as a camera and equipping another device, handheld or otherwise, with the ability to generate and display visual tags, in the form of barcodes or other encoded symbologies, on the device's display. However, the problem of limited visual tag data storage and data communication is exasperated in the handheld device because the number of pixels in the display of such devices is limited, the camera capabilities in such devices are generally limited and other factors. In the case of RFID communication, as previously noted, the amount of information that can be transmitted from any one single tag is limited by the memory capacity of the tag.
Numerous solutions have recently been developed to address the problems related to limited data communication in applications using tags. In one method, information transmitted from a tag initiates some other supplemental form of wireless communication, whereby the supplemental communication means provides the primary source of information transfer. For example, the tag may be limited to containing a network address of a sharing device and an information content address on the sharing device. Once this tag is read, the reading device initiates a supplemental communication means, such as a short-range wireless communication means, like Bluetooth®, IR or the like, to communicate with the sharing device, using the network address and content address provided by the tag. This allows for a larger amount of data to be communicated from the sharing device than would otherwise be possible from the tag. However, this type of data transfer is only possible if the reading device is equipped with a supplemental communication means, such as a short-range wireless communication means. Additionally, even if the reading device is sufficiently equipped with the requisite supplemental communication means, certain short-range means may be prone to service outages. Therefore a need exists to develop a method to communicate large volumes of information that solely relies on tags as the transmission mechanism.
In one highly speculative proposed method that relies solely on tags, the contents of an entire book is communicated using a series of 1000 or more 2D barcodes, such as MaxiCode symbology, displayed on a screen and subsequently captured and decoded by a combination Personal Digital Assistant (PDA) and camera. However, according to this proposed method the suggested data transfer rate is 1000,000 bytes per 3.125 seconds, which is significantly beyond current technology capability. The PDA, or any other similar digital device, would not be capable of decoding the images at such a high-speed rate. The proposed method provides for any actual technical solution as to how such data transfer could be accomplished and provides, merely, a desire that this method could be feasible. It is noted that the typical time needed to decode a single barcode image will vary based on the image quality, lighting, shadows, pixel alignment and the like. In practice, individual barcodes require ample display time to assure successful decoding and this factor substantially slows down the data transfer rate.
Therefore a need exists to develop methods, devices and computer program applications that provide for large volumes of data to be communicated in applications that rely, solely, on tags as the transmission medium. Such methods, devices and applications will provide for reasonable and currently attainable transfer rates to be employed. In addition, the desired methods, devices and applications will allow for a variance in tag decode time, allowing for multiple tags to be decoded in series with each tag being decoded at its own decode rate.